Wingspan 32 to 42 mm. One of several similar 'mimic' species, known as Clearwings, this is one of the largest.

Where willows are present.

Best looked for in July, as the adults emerge and rest low down on the trunks of various willows.

The eggs are laid on the bark, and the larvae burrow into the wood, feeding internally.

Widespread in Britain. In a recent survey to determine the status of all macro moths in Britain this species was classified as common.

Occasional in Leicestershire and Rutland. L&R Moth Group status = C (very scarce resident or rare migrant).